This invention relates to a vibrator and a vibratory gyroscope used for an angular rate sensor measuring a turning angular rate in a turning system, a device for measuring a linear acceleration and a method of measuring a turning angular rate.
Up to now, as an angular rate sensor used for detecting a turning angular rate in a turning system, a vibratory gyroscope using a piezoelectric material has been used for detecting position of an aircraft, a ship and a space satellite. Recently, the gyroscope is used in a car-navigation system, a movement detecting mechanism in a VTR or a still camera.
Such a vibratory gyroscope utilizes a Coriolis force, which is generated when an angular movement is applied to a vibrating object in a direction perpendicular to the vibratory direction. Its mechanism may be understood by using a dynamic model (for example, "Handbook of Elastic Wave Device Technologies" (Danseiha-Sosi Gijutsu Handbook) published by Ohm, Inc., pp.491 to 497). Various kinds of piezoelectric vibratory gyroscopes have been proposed. For example, a Sperry tuning-fork gyroscope, a Watson tuning-fork gyroscope, a regular-triangle prism-shaped tuning-piece gyroscope, a cylindrical tuning-piece gyroscope are known.